fix: land pane opens on the live scrollback tail (0.11.1)

[vinicius91carvalho]

Summary

• Opening / switching a tab or pane now lands on the live tail instead of the oldest scrollback.
• Root cause: the terminal <pre> uses overflow-x-auto for wide TUI tables; CSS then forces overflow-y: auto, flex shrinks that <pre> to the viewport, and it becomes the vertical scroller — so ChatMessageList stickiness was a no-op.
• Fix: shrink-0 on the pre, block (not flex-col) scrollport, stop the mirror wrapper from becoming a second vertical scroller; also re-pin when content grows after open.

Evidence (headless Chromium against live http://127.0.0.1:8787)

Phone viewport 390×844, pane w5:p2 (~261 lines of Cursor output).

Before — vertical scroll lived on <pre>; list never overflowed; stuck at top:

element	scrollTop	scrollHeight	clientHeight	scrollable	atBottom
ChatMessageList (overflow-y-auto)	0	420	420	no	yes (vacuously)
<pre> (AnsiOutput)	0	3945	381	yes	no

After (bun run build, same probe) — list is the scroller and opens pinned to the tail:

element	scrollTop	scrollHeight	clientHeight	scrollable	atBottom
ChatMessageList (overflow-y-auto)	4674	5094	420	yes	yes
<pre> (AnsiOutput)	0	5055	5055	no	yes

Second pane check (w6:p2, ~361 lines): list scrollTop=6084 / scrollHeight=6504 / clientHeight=420, atBottom=true; <pre> not scrollable.

Test plan

• Hard-refresh the PWA (or reopen the installed app) so the new bundle loads
• Open a long pane from home — first paint should show the prompt/tail, not the Cursor Agent banner
• Switch tabs in the in-pane tab strip — each tab should land on its live tail
• Scroll up to read history — live updates should freeze; "jump to latest" still works
• Wide no-wrap TUI tables still pan horizontally
• cd web && bun run test / bun run test (root) green

Made with Cursor